Adjustable jet and its application in an apparatus for recycling the exhaust gases of an internal combustion engine

ABSTRACT

An adjustable gas jet in which the passage for the gas is defined by two orifices in two very thin-edged walls one of which is rotatable by a rotary member extending out of the body of the jet. The section of the passage depends on the overlapping of the orifices. The jet is employed in an exhaust gas recycling conduit for a combustion engine which puts the exhaust pipe in communication with the induction pipe of the engine.

United States 'atent Bertrand et al.

ADJUSTABLE JET AND ITS APPLICATION IN AN APPARATUS FOR RECYCLING THE EXHAUST GASES OF AN INTERNAL COMBUSTION ENGINE Inventors: Bernard Bertrand, 78 Aubergenville; Claude Lesueur, 95 Argenteuil, both of France Assignees: Automobiles Peugeot; Regie Nationale Des Usines Renault, Billancourt, France Filed: Oct. 7, 1971 Appl. No.: 187,436

Foreign Application Priority Data Oct. 13, l970 France ..7036959 Jan. 29, 1968 France ..68l37750 U.S.Cl. .....123/1l9A Int. Cl ..F02m 25/06 Field of Search ..60/278; 123/119 A Primary ExaminerDouglas Hart Att0rr zeyBurns, Doane, Swecker & Mathis [57] ABSTRACT An adjustable gas jet in which the passage for the gas is defined by two orifices in two very thin-edged walls one of which is rotatable by a rotary member extending out of the body of the jet. The section of the passage depends on the overlapping of the orifices.

Thejet is employed in an exhaust gas recycling conduit for a combustion engine which puts the exhaust pipe in communication with the induction pipe of the engine.

7 Claims, 4 Drawing Figures ADJUSTABLE JET AND ITS APPLICATION IN AN APPARATUS FOR RECYCLING THE EXHAUST GASES OF AN INTERNAL COMBUSTION ENGINE The present invention relates to an adjustable jet adapted to regulate a gas flow somewhat similar to the general type described in U.S. Pat. No. 3,589,380, filed Jan. 10, 1969, and to its application to the regulation of the flow exhaust gases reintroduced in the induction circuit of an internal combustion engine.

The invention provides an adjustable jet comprising means defining a body, means defining a first wall, said first wall being fixed relative to said body and having a first smooth face, a first inner thin portion, a first outer annular thick portion defining a first cavity on a side of said first wall opposed to said first smooth face, a first orifice which extends axially through said first thin portion and has a given minimum transverse extent, said first cavity being larger than said first orifice so as to be transversely set back from said first orifice throughout the periphery of said first orifice, said first thin portion having a thickness which is a minor fraction of said transverse extent of said first orifice whereby said first orifice is defined by a first edge affording only a small surface for deposit of dust and dirt thereon, means defining a second wall rotatable relative to said body and having a second smooth face, a second inner thin portion, a second outer annular thick portion defining a second cavity on a side of said second wall opposed to said second smooth face, a second orifice which extends axially through said second thin portion and has a given minimum transverse extent, said second cavity being larger than said second orifice so as to be transversely set back from said second orifice throughout the periphery of said second orifice, said second thin portion having a thickness which is a minor fraction of said transverse extent of said second orifice whereby said second orifice is defined by a second edge defining only a small surface for deposit of dust and dirt thereon, said second smooth face being in slidable contact with said first smooth face and slidable between a first position in which said orifices are in alignment and a second portion in which said first orifice is completely masked by said first wall, means maintaining said smooth faces in sliding contact with each other and rotary means rotatable relative to said body and drivingly connected to said second wall for rotating said second wall relative to said first wall between said two positions.

The advantageous effects of a partial recycling of exhaust gases are known as concerns reduction in their nitrogen oxide content. Now, if this recycling is to have its full effect, the flow of gas reintroduced in the induction pipe of the engine must be correctly regulated in accordance with the load on the engine. In most of the known devices, whether of the slide or valve type, the regulation is insufficiently progressive. This can be partially remedied by reintroducing the gases upstream of the gas butterfly valve. It is then the latter which ensures the regulation at the same time as the regulation of the air flow. However, this arrangement has the drawback of rapidly soiling the carburetor.

Another object of the invention is to provide an apparatus for recycling the exhaust gases ofa combustion engine comprising a recycling conduit in which is inserted a flow regulating device, wherein said regulating device is an adjustable jet comprising means defining a first wall, said first wall being fixed and having a smooth face, an inner thin portion, an outer annular thick portion defining a cavity on a side of said first wall opposed to said smooth face, an orifice which extends axially through said thin portion and has a given minimum transverse extent, said cavity being larger than said orifice so as to be transversely set back from said orifice throughout the periphery of said orifice, said thin portion having a thickness which is a minor fraction of said transverse extent of said orifice whereby said orifice is defined by an edge affording only a small surface for deposit of dust and dirt thereon, means defining a second wall adapted to slide along said smooth face and mask to a varying extent said orifice so as to define a passage of variable section through said first wall, a movable element integral with said second wall, elastically yieldable means maintaining said second wall in sliding contact with said smooth face.

Such a device is simple, precise and unaffected by soiling and therefore perfectly remedies the drawbacks of known devices.

Further features and advantages of the invention will be apparent from the ensuing description with reference to the accompanying drawing.

In the drawing:

FIG. 1 is a sectional view of a jet according to the invention;

FIG. 2 is an elevational view, with parts cut away, of the jet shown in FIG. 1;

FIG. 3 is a plan view of an engine including an exhaust-gas recycling device according to the invention, and

FIG. 4 is a view partly in elevation and partly in section of a modification of the control device shown in FIG. 3.

An embodiment of an adjustable jet G according to the invention will first be described with reference to FIGS. 1 and 2. The jet comprises a body 21 and a cover 22 interconnected in ajoint plane by screws 23.

A thin sheet 24, for example metal foil, is clamped between the body 21 and the cover 22. It has an orifice 25 whose edge throughout the perimeter of the orifice is located within an aperture 26 which is provided in the body 21, and communicates with a chamber 27 also formed in the body 21. A conduit 28 is connected to the chamber 27.

A shaft 29 is rotatably mounted in a bore 21a in the body 21 and terminates within the cover 22 in a screwthreaded portion 29a having two flat faces 29b. A second thin sheet 30 is connected to rotate with the shaft 29 owing to the action of the flat faces 29b and applied against the fixed sheet 24 by a washer 31 which is connected to rotate with the shaft 29 and biased by a spring 32 which bears against a nut 33. The sheet 30 has an orifice 34 whose edge is, throughout the perimeter of the orifice 34, located within an aperture 35 provided in the washer 31. The cover 22 defines a chamber 36 connected to a conduit 37.

The particular shapes of the orifices 25 and 34 will be seen in FIG. 2, these shapes enabling a particularly precise and progressive regulation to be achieved. The orifice 25 is in the shape of an elongated slot which is roughly radially disposed with respect to the shaft 29 and has a rectilinear edge 25a and a curvilinear edge 25b, the width of the orifice increasing in the radially outward direction. The orifice 35 is in the shape of a curvilinear triangle having a first side 34a roughly concentric with the axis of rotation of the moving part or shaft 29 and at the same distance from this axis as the narrow end of the orifice 25, a second side 34b roughly radially disposed with respect to the axis of rotation of the shaft 29 and rectilinear and having a length which roughly corresponds to the length of the orifice 25, and a third side 34c which is curvilinear.

The operation of a jet of the type shown in FIGS. 1 and 2 in its application to a device for recycling the exhaust gases of an internal combustion engine M (FIG. 3) will now be described.

FIG. 3 shows the engine M with its carburetor C in the induction manifold A, the exhaust manifold E, the silencer S and the fan V.

The recycled exhaust gases are taken off in the silencer S by the conduit 37 and their flow is controlled by the jet G after which they are conducted by the conduit 28 into the induction manifold A on the downstream side of the carburetor C. In this embodiment, the shaft 29 is common with the shaft of the gas butterfly valve of the carburetor so that it is the load on the engine which controls the regulation of the jet. Note moreover that the conduit 37 passes in front of the fan V so as to cool the reintroduced gases.

It can be seen that communication between the conduits 28 and 31 (FIG. 1) occurs only when the orifice 25 of the sheet 24-and the orifice 34 of the sheet 30 are at least partly superimposed. It is also clear that the section of passage is in all cases defined throughout its perimeter by a thin wall. Such a jet has therefore the enormous advantage of being completely unaffected by soiling so that it is able to keep its characteristics over a period of time.

Preferably, when the gas butterfly valve is completely closed and the engine is under very low load, the orifice 34 is in the position shown in dot-dash line in FIG. 2 and, when the gas butterfly valve is completely open, this orifice 34 is in the position shown in full line in FIG. 2.

Therefore it is only for intermediate operational conditions that a recycling is effected and it is very easy to choose the shapes of the orifices 25 and 34 to obtain in each position a section of gas passage corresponding to the most suitable gas flow. It is in particular possible with the illustrated profiles to have a different progressivity when opening and starting with low engine loads and then when closing in the region of the high loads.

In the modification shown in FIG. 4, the jet G is identical to that shown in FIGS. 1 and 2 but it is controlled by a depression capsule 38 of known type. This capsule comprises a chamber 39 communicating with a conduit 40 connected to the induction manifold. This chamber 39 is defined partly by a diaphragm 41 of the rolling type which is maintained in position by a piston 42. The latter acts on a wire 43 which extends around a reel 44 connected to rotate with the rotatable shaft 29 of the jet. A return spring 45 exerts on the reel 44 an action opposed to that of the wire 43 so as to put the assembly in equilibrium.

Having now described our invention what We claim and desire to secure by Letters Patent is:

1. An apparatus for recycling the exhaust gases of a combustion engine comprising an exhaust gas recycling conduit and a flow regulating device inserted in said conduit, said regulating device being an adjustable jet comprising means defining a first wall, said first wall being fixed and having a smooth face, an inner thin portion, an outer annular thick portion defining a cavity on a side of said first wall opposed to said smooth face, an orifice which extends axially through said thin portion and has a given minimum transverse extent, said cavity being larger than said orifice so as to be transversely set back from said orifice throughout the periphery of said orifice, said thin portion having a thickness which is a minor fraction of said transverse extent of said orifice whereby said orifice is defined by an edge affording only a small surface for deposit of dust and dirt thereon, means defining a second wall adapted to slide along said smooth face and mask to a varying extent said orifice so as to define a gas flow passage of variable section through said first wall, a movable element integral with said second wall, elastically yieldable means engaging said movable element and maintaining said second wall in sliding contact with said smooth face, and means responsive to conditions of operation of said engine and connected to said movable element to move said movable element and vary said gas flow passage in accordance with said conditions of operation of said engine.

2. An apparatus for recycling the exhaust gases of a combustion engine comprising an exhaust gas recycling conduit and a flow regulating device inserted in said conduit, said regulating device being an adjustable jet comprising means defining a body, means defining a first wall, said first wall being fixed relative to said body and having a first smooth face, a first inner thin portion, a first outer annular thick portion defining a first cavity on a side of said first wall opposed to said first smooth face, a first orifice which extends axially through said first thin portion and has a given minimum transverse extent, said first cavity being larger than said first orifice so as to be transversely set back from said first orifice throughout the periphery of said first orifice, said first thin portion having a thickness which is a minor fraction of said transverse extent of said first orifice whereby said first orifice is defined by a first edge affording only a small surface for deposit of dust and dirt thereon, means defining a second wall rotatable relative to said body and having a second smooth face, a second inner thin portion, a second outer annular thick portion defining a second cavity on a side of said second wall opposed to said second smooth face, a second orifice which extends axially through said second thin portion and has a given minimum transverse extent, said second cavity being larger than said second orifice so as to be transversely set back from said second orifice throughout the periphery of said second orifice, said second thin portion having a thickness which is a minor fraction of said transverse extent of said second orifice whereby said second orifice is defined by a second edge defining only a small surface for deposit of dust and dirt thereon, said second smooth face being in slidable contact with said first smooth face and slidable between a first position in which said orifices are in alignment and a second position in which said first orifice is completely masked by said first wall, means maintaining said smooth faces in sliding contact with each other and rotary means rotatable relative to said body and drivingly connected to said second wall for rotating said second wall relative to said first wall between said two positions, and means responsive to conditions of operation of said engine and connected to said rotary means to rotate said rotary means and vary said gas flow passage in accordance with said conditions of operation of said engine.

3. An apparatus as claimed in claim 2, wherein said rotary means is a shaft rotatably mounted relative to said body.

4. An apparatus as claimed in claim 3, wherein said shaft is an extension of the butterfly valve of the carburetor ofthe engine.

5. An apparatus as claimed in claim 3, comprising a reel fixed to said shaft, a flexible filament extending round said reel and having one end fixed to said reel, and a pressure-responsive capsule to which an end of said filament opposed to the first-mentioned end is connected so as to be shifted by said capsule in response to pressure change, said capsule being exposed to the depression prevailing in the induction pipe of the engine.

6. An apparatus as claimed in claim 1, wherein said recycling conduit passes in the vicinity of the fan of the engine.

7. An apparatus as claimed in claim 2, wherein said recycling conduit passes in the vicinity of the fan of the engine. 

1. An apparatus for recycling the exhaust gases of a combustion engine comprising an exhaust gas recycling conduit and a flow regulating device inserted in said conduit, said regulating device being an adjustable jet comprising means defining a first wall, said first wall being fixed and having a smooth face, an inner thin portion, an outer annular thick portion defining a cavity on a side of said first wall opposed to said smooth face, an orifice which extends axially through said thin portion and has a given minimum transverse extent, said cavity being larger than said orifice so as to be transversely set back from said orifice throughout the periphery of said orifice, said thin portion having a thickness which is a minOr fraction of said transverse extent of said orifice whereby said orifice is defined by an edge affording only a small surface for deposit of dust and dirt thereon, means defining a second wall adapted to slide along said smooth face and mask to a varying extent said orifice so as to define a gas flow passage of variable section through said first wall, a movable element integral with said second wall, elastically yieldable means engaging said movable element and maintaining said second wall in sliding contact with said smooth face, and means responsive to conditions of operation of said engine and connected to said movable element to move said movable element and vary said gas flow passage in accordance with said conditions of operation of said engine.
 2. An apparatus for recycling the exhaust gases of a combustion engine comprising an exhaust gas recycling conduit and a flow regulating device inserted in said conduit, said regulating device being an adjustable jet comprising means defining a body, means defining a first wall, said first wall being fixed relative to said body and having a first smooth face, a first inner thin portion, a first outer annular thick portion defining a first cavity on a side of said first wall opposed to said first smooth face, a first orifice which extends axially through said first thin portion and has a given minimum transverse extent, said first cavity being larger than said first orifice so as to be transversely set back from said first orifice throughout the periphery of said first orifice, said first thin portion having a thickness which is a minor fraction of said transverse extent of said first orifice whereby said first orifice is defined by a first edge affording only a small surface for deposit of dust and dirt thereon, means defining a second wall rotatable relative to said body and having a second smooth face, a second inner thin portion, a second outer annular thick portion defining a second cavity on a side of said second wall opposed to said second smooth face, a second orifice which extends axially through said second thin portion and has a given minimum transverse extent, said second cavity being larger than said second orifice so as to be transversely set back from said second orifice throughout the periphery of said second orifice, said second thin portion having a thickness which is a minor fraction of said transverse extent of said second orifice whereby said second orifice is defined by a second edge defining only a small surface for deposit of dust and dirt thereon, said second smooth face being in slidable contact with said first smooth face and slidable between a first position in which said orifices are in alignment and a second position in which said first orifice is completely masked by said first wall, means maintaining said smooth faces in sliding contact with each other and rotary means rotatable relative to said body and drivingly connected to said second wall for rotating said second wall relative to said first wall between said two positions, and means responsive to conditions of operation of said engine and connected to said rotary means to rotate said rotary means and vary said gas flow passage in accordance with said conditions of operation of said engine.
 3. An apparatus as claimed in claim 2, wherein said rotary means is a shaft rotatably mounted relative to said body.
 4. An apparatus as claimed in claim 3, wherein said shaft is an extension of the butterfly valve of the carburetor of the engine.
 5. An apparatus as claimed in claim 3, comprising a reel fixed to said shaft, a flexible filament extending round said reel and having one end fixed to said reel, and a pressure-responsive capsule to which an end of said filament opposed to the first-mentioned end is connected so as to be shifted by said capsule in response to pressure change, said capsule being exposed to the depression prevailing in the induction pipe of the engine.
 6. An apparatus as claimed in claim 1, wherein said recycling conduit Passes in the vicinity of the fan of the engine.
 7. An apparatus as claimed in claim 2, wherein said recycling conduit passes in the vicinity of the fan of the engine. 